There are currently no standard diagnostic tools in clinical practice that can be used to quantitatively assess tremors, such as those caused by Parkinson's disease or fatigue. In current practice, symptoms are observed and evaluated with clinical protocols, but the results are subjective and can differ from person to person.
The frequency distribution of tremor syndromes has been investigated based on etiology. Voluntary hand movements range between 0 and 2 Hz while pathological tremors range between 3 and 12 Hz. Although detecting pathological tremors may help early diagnosis of diseases, such as Parkinson's disease, the frequency range of such tremors makes it difficult to observe tremors with the eyes.
Recently, research has been conducted using accelerometers with the goal of detecting the frequencies of tremors. For example, handheld devices having embedded accelerometers, such as smart phones, have been proposed to monitor hand tremors.
These devices, however, present an additional load, physically or subconsciously, to the patients who may not completely relax their muscles. This makes it more difficult to detect the tremors. Aside from that, the amplitude of the hand tremor cannot be accurately detected using an accelerometer, which detects the acceleration of an object instead of its motion.
From the above discussion, it can be appreciated that it would be desirable to have a system and method for accurately detecting tremors.